Containers having openings protected by doors, such as drawers and closets, are used for storing objects including valuable objects. A user gains access to the container through an opening by opening the door. After placing an object in the container, the user then uses the door to close the opening. However, in many instances, a user may neglect to close the container door properly. As such, there is a need for a notification device to notify the user if the container door is not closed properly. In other instances, after the user closes the door properly, the user desires notification if another user opens the door to the container. Further, for container with multiple openings and doors, the user desires notification of which door has been opened.